The invention relates to a device for adjusting the phase angle of a camshaft of an internal combustion engine with a drive gear for driving a camshaft accommodated in a coaxial arrangement relative to the camshaft and with an electric motor for rotating the camshaft relative to the drive gear, wherein the electric motor has two concentrically arranged rotors, of which the one is connected to the camshaft and the other to the drive gear.
To obtain optimum values for fuel consumption and exhaust emissions in different areas of the internal combustion engine's operating characteristics, the valve timing must be varied in dependence of different operating parameters. An elegant manner of varying the valve timing is realized by rotating the camshaft relative to its driving gear. The camshaft of an internal combustion engine is usually driven by a sprocket wheel, which is connected to the crankshaft via a drive chain, or by a drive gear configured as a pulley, which is connected to the crankshaft via a toothed belt.